The present invention relates to a pyroacoustic device constituting a jammer or decoy for protecting sub-marines or surface vessels.
Document U.S. Pat. No. 3,799,094 describes a pyrotechnic device for diverting an underwater system. The device comprises a vehicle which carries a plurality of charges that are distributed generally over a cylinder centered on a horizontal axis. The charges are urged radially outwards by respective springs and they are freed cyclically by a rod driven in rotation by a shaft. Each of the charges has a membrane so that as the charge sinks, the pressure on the payload increases, leading at a given depth, to heating capable of causing initiation. The document thus describes a device in accordance with the preamble of accompanying claim 1.
An object of the present invention is to propose a novel device that is more effective than previously known devices against the homing systems of torpedoes.
In the context of the present invention, this object is achieved by a device comprising:
a structure suitable for forming a positioning device for controlled positioning under water; and
a case connected to the positioning device, which case contains:
a plurality of charges each suitable for generating an acoustic effect; and
control means suitable for initiating said plurality of charges in a controlled sequence characterized by the fact that the control means are adapted to define a time interval between initiation of two successive charges lying in the range 0.2 seconds (s) to 0.5 s.